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Printing Holy Grail Discovered

2004-06-09

There are currently lots of fine things being said about the HP Photosmart 7xxx range, particularly their amazing black & white printing capability, but mainly by those lucky people who have already taken a chance on one. The rest of the world, or at least the part that skulks in Internet photographic fora, seems content to continue swapping tips on unclogging Epson heads while pointedly ignoring the HP users raving about their great printers. I’m delighted… overjoyed… ecstatic with my 7660 (ex-Epson users tend to be like that when they finally switch to any other brand of frickin’ printer) under Linux, so here are a few hints on making it work well for photo printing.

The USB side of things should work fine, and if you’re using a recent distro or an up to date foomatic database, there should be a driver entry under the CUPS setup.

In the GIMP print dialogue, select PostScript Level 2 as the printer model then locate the PPD file. Assuming you’ve already configured CUPS, this should be in the /etc/cups/ppds directory (under Red Hat/Fedora). Change the print command options; delete the -oraw part and add -o'PrintoutMode=Photo' to ensure the printer goes into photo mode (you can get a list of other options with lpoptions -l). Most of the other dropdown menus will be grayed out, mainly because the printer autodetects the media type and tailors the ink output appropriately. If you’re using the HP no. 59 grey cartridge then either colour or greyscale will work for B/W images. Toned images seem to come out well with the #59 cart in colour mode (the standard #57 cart supplies the coloration).

I had several months of excellent prints from my P7660, but then I began to see some really poor results. Banding, consisting of broken ink layering, started to appear across the images. At first, this only seemed to occur with Ilford Classic Gloss paper. Then the problem spread to other gloss papers. Finally, even prints on matte paper were affected. I tried running cleaning cycles. I tried new cartridges. I tried other brands of paper. Finally, in desperation, I … I … booted Windows. Installed the bundled HP driver (um, after three hours and a hundred reboots to update IE to the right level) and … got a perfect print (despite the rather limited image-handling software that HP supply). Humph.

Back to Linux for some deeper investigation, now I knew the printer worked correctly. I noticed that Ghostscript was preprocessing the output at 300dpi, whereas the printer is capable of 1200dpi. So I went into the CUPS configuration and set up a new photo-specific queue for the same device, with the output explicitly set to “1200dpi, Photo” rather than “Controlled by Printout Mode”. Using this queue, Ghostscript processed the output at 1200dpi resolution and the result was a perfect print. Once more.

I have no idea why the output quality changed and degraded so subtly, but I suspect it may have something to do with the behaviour of either CUPS or Ghostscript being altered by one of the many Fedora updates. Theoretically, the default settings should have worked fine (and indeed did for a while), but at least this way I know the output will always be handled at the maximum resolution no matter what.

Some good things about the P7660:
* B/W printing, as already mentioned, is superb. I have no idea how it compares to traditional wet prints (some claim it equals or betters them, depending on your skill level in the darkroom), but they’re Good Enough For Me.
* Colour rendition appears almost exactly like the onscreen image without any tweaking or profiling, although doubtless proper calibration would make up the remaining few percent difference. However, the 7660 tends to print lighter so you usually have to reduce the gamma by 10-20% and maybe boost saturation slightly.
* There are almost no head clogging problems at all. Even if it happens, you can simply replace the cartridge to get a new head (which partly explains their phenomenally high pricing, although “gouging the consumer” would seem to be a major component too). Contrast this with the Epson 830 (or indeed any Epson), which clogs within the first seven days or five seconds of a dust molecule landing on the casing, whichever comes sooner, and then stays clogged despite copious cleaning, floods of Windolene, servicing, sanding or a damn good bashing with a heavy mallet prior to tossing the useless heap of junk in the bin (pant, pant, pant…).
* Even printing direct from a memory card produces acceptable snapshots. Minor issues: continually swapping cartridges for different types of printing (there are varying optimum combinations for text, colour photos and B/W photos) is a pain, as is the printer’s insistence on running a calibration test (with paper) each time a new cartridge of a particular type is inserted.

Some people feel that the more expensive 7960 is the one to go for, because its imaging algorithm is superior and its ability to hold three carts at once means a greater greyscale range and less swapping. That may be true, but if you can’t afford the high end model, don’t sweat it; I doubt you’ll be dissatisfied with the budget range.